In a typical electrophotographic printing apparatus, a light image of an original to be copied is recorded in the form of an electrostatic latent image upon a photosensitive member. The latent image is subsequently rendered visible by application of electroscopic thermoplastic resin particles, which are commonly referred to as toner. The visible toner image is then in a loose powdered form and is usually fused, using a fusing assembly, upon a support, which may be an intermediate member, or a print medium such as paper.
A conventional fusing assembly may include a fuser roller and a pressure roller, which may be configured to include a roll pair maintained in pressure contact or a belt member in pressure contact with a roll member. In a fusing process, heat may be applied by heating one or both of the fuser roller and the pressure roller.
The fuser roller may include a coating or “topcoat” to achieve target levels of toner release and thermal conductivity. Fluoropolymers, including polytetrafluoroethylene (“PTFE”) and its copolymers such as perfluoroalkoxy (“PFA”) resins, are often used in topcoats because they possess low surface energy to provide superior toner release. However, few materials have all desired properties. For example, some materials having low surface energy often have relatively low thermal conductivity, thus requiring more energy for fusing. Incorporating fillers into the topcoat to increase thermal conductivity has been attempted to remedy this problem, but this often results in poor toner release performance. Therefore, a topcoat having increased thermal conductivity while maintaining good toner release properties would be highly desired.